Thursday, August 21, 2014

New vaccine against tuberculosis and leprosy

A new vaccine offers protection against tuberculosis and leprosy :
Aug 20, 2014 : In a breakthrough, US researchers have found that an
improved tuberculosis vaccine can offer strong protection against
leprosy. In lab experiments over mice, researchers found that rBCG30, a
recombinant variant of BCG that over expresses a highly abundant 30 kDa
protein of the tuberculosis bacterium known as Antigen 85B, is superior
to BCG in protecting against tuberculosis in animal models, and also cross protects against leprosy.
In addition, they found that boosting rBCG30 with the antigen 85B
protein also expressed by the leprosy bacillus provides considerably
stronger protection against leprosy.

The original article published in : Infection and Immunity
( http://iai.asm.org/content/82/9/3900.abstract)rBCG30-Induced Immunity and Cross-Protection against Mycobacterium
leprae Challenge Are Enhanced by Boosting with the Mycobacterium
tuberculosis 30-Kilodalton Antigen 85BThomas P. Gillisa, Michael V. Tulliusb and Marcus A. Horwitzb J. L. Flynn, EditorABSTRACTLeprosy remains a major global health problem and typically occurs in
regions in which tuberculosis is endemic. Vaccines are needed that
protect against both infections and do so better than the suboptimal
Mycobacterium bovis BCG vaccine. Here, we evaluated rBCG30, a vaccine
previously demonstrated to induce protection superior to that of BCG
against Mycobacterium tuberculosis and Mycobacterium bovis challenge in
animal models, for efficacy against Mycobacterium leprae challenge in a
murine model of leprosy. rBCG30 overexpresses the M. tuberculosis 30-kDa
major secretory protein antigen 85B, which is 85% homologous with the
M. leprae homolog (r30ML). Mice were sham immunized or immunized
intradermally with BCG or rBCG30 and challenged 2.5 months later by
injection of viable M. leprae into each hind footpad. After 7 months,
vaccine efficacy was assessed by enumerating the M. leprae bacteria per
footpad. Both BCG and rBCG30 induced significant protection against M.
leprae challenge. In the one experiment in which a comparison between
BCG and rBCG30 was feasible, rBCG30 induced significantly greater
protection than did BCG. Immunization of mice with purified M.
tuberculosis or M. leprae antigen 85B also induced protection against M.
leprae challenge but less so than BCG or rBCG30. Notably, boosting
rBCG30 with M. tuberculosis antigen 85B significantly enhanced
r30ML-specific immune responses, substantially more so than boosting
BCG, and significantly augmented protection against M. leprae challenge.
Thus, rBCG30, a vaccine that induces improved protection against M.
tuberculosis, induces cross-protection against M. leprae that is
comparable or potentially superior to that induced by BCG, and boosting
rBCG30 with antigen 85B further enhances immune responses and protective
efficacy.
****

The next step is to
test the rBCG30 vaccine for efficacy in humans against TB. If it is effective against TB, then the next step would be to test its effectiveness in humans against leprosy.

Title photo : SUNRISE

The photograph of 'sunrise' used in the title is taken by me using Sony digicam. No post-processing except I cropped it to fit in the place. Full series of the photos of that sunrise can be seen if you click on the label below: Photos